I'll probably use discord, or any of the voice chat apps on my phone. I only play with friends, not random people so we can use whatsapp or any app that does voice over ip. I will mainly play locally with my boyfriend, so we'll be yelling live at each other in the same room.
I played hours of New horizons with the Nintendo app and it worked quite well with the lobby, but I guess it has a cost for the servers and it depends on the game and the developper if it's enabled or not.
The party chat on PS5 is pretty easy to set up, but I often find myself calling friends on the phone when we play together anyway. It's nice to have options.
For those who don't want to use discord on the switch version and prefer to wait for the PC version... won't you have to use Discord on PC too ? I doubt they add an integrated voice chat in the port.